Low dropout regulator

Abstract

The invention discloses a low dropout regulator, which comprises an error amplifier, a buffer circuit, a P-channel metal oxide semiconductor (PMOS) regulation transistor, an N-channel metal oxide semiconductor (NMOS) push-pull tube, a voltage division feedback circuit, a compensation circuit and an output circuit, wherein the gate of the PMOS regulation transistor is connected with the output end of the buffer circuit, the source of the PMOS regulation transistor is connected with power voltage, and the drain of the PMOS regulation transistor is used as the output end of the low dropout regulator; the gate of the NMOS push-pull tube is connected with the output end of the error amplifier, the drain of the NMOS push-pull tube is connected with the drain of the PMOS regulation transistor, and the source of the NMOS push-pull tube is grounded; and the error amplifier, the compensation circuit, the buffer circuit, the PMOS regulation transistor, the voltage division feedback circuit and an output circuit form a main control loop, and the error amplifier, the compensation circuit, the NMOS push-pull tube, the voltage division feedback circuit and the output circuit form an auxiliary control loop. According to the low dropout regulator, the transient response of the regulator can be quickened, and the accuracy of output voltage can be improved.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to a low-dropout linear regulator circuit. Background technique [0002] Low Dropout Regulator (LDO) is a step-down DC linear regulator. With the development of SOC technology, it is widely used in industries such as computers, communications, instrumentation, consumer electronics, and camera monitoring. . Although compared with the DC-DC switching voltage converter, the efficiency of the LDO is lower, but it has the advantages of fewer peripheral components, small ripple, low noise, small chip area, and simple circuit structure, so the LDO is used in power management chips. has always held a large proportion. [0003] With the improvement of integration, more and more LDOs are integrated into the SOC chip as a sub-module of the SOC (System on Chip, System on Chip) chip to supply power to a key module, and the powerful SOC chip integrates It is common to have multiple...

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